The present invention relates to a reverse molded (profile up, as molded) wood composite article particularly useful for the manufacture of a wainscot panel, and also useful as a door skin or door-facing surface, and to a method of making the reverse molded wood composite article, having an upwardly inclined profile molded upwardly from a planar base portion of the article. More particularly, the molded wood composite article of the present invention is made from a cellulosic mat containing a combination of cellulosic fibers, preferably including at least about 40% by weight, preferably at least about 60%, softwood fibers, (from trees that produce cones) such as all species of pine, and fir, e.g., Southern Pine, based on the total dry fiber weight, and a natural or synthetic binder, such as a phenol formaldehyde or urea formaldehyde resin. The cellulosic mat includes at least about 80% refined, fibrillated cellulosic fibers, e.g., a fiberboard mat, such as that hot-pressed to produce hardboard. The upper surface of the molded article has excellent molding die fidelity and may have a smooth finish or may be embossed to simulate a hardwood grain pattern, such as oak, simulating furniture grade natural wood. The articles are molded from a planar layer or mat of cellulosic fibers, e.g., a fiberboard mat, made either by the wet process or the dry process, preferably the dry process. In a preferred embodiment, the fiberboard mat is one to three inches in thickness before molding, and after molding is xe2x85x9 to xc2xc inch in thickness having co-planar stiles and rails, and planar back surfaces surrounding the molded panels, such that the co-planar back surfaces are adapted for flush contact against a wall or door surface, particularly between a wall base board and chair rail, as a wainscot outer wall surface lining for an interior household wall. In accordance with another embodiment of the invention, the reverse molded panels are manufactured in a kit, including a plurality of differently sized panels adapted to completely line an interior wall, regardless of wall dimension.
Man-made boards, such as fiberboard, e.g., hardboard, commonly are embossed downwardly on their intended visible major outer surface in the manufacture of interior paneling, exterior siding, and particularly in the manufacture of door skins, such that exterior surfaces, such as stiles and rails, are the highest structure of the embossed product. The prior art discloses that it is difficult to reverse mold and to emboss deep draws into a fiberboard panel due to stretching and breaking of the fibers. A reverse molded fiberboard is stretched more on its visible outer surface than on its interior surface (surface in contact with a raised mold surface) making reverse molding much more difficult when attempting to provide sharp, crisp design detail in a raised panel that simulates natural wood millwork. As disclosed in the following U.S. patents, reverse molding and embossing deep draws into a fiberboard panel generally requires one or more of multiple press steps, post mold curing at elevated temperatures, a foil or high resin content outer surface portion, and/or high binder resin content of about 5-25%, preferably at least 10% by weight of the product: U.S. Pat. No. 4,061,813 Geimer; U.S. Pat. No. 4,378,265 Kiss; U.S. Pat. No. 4,552,797 Munk; U.S. Pat. No. 4,610,900 Nishibori; U.S. Pat. No. 4,612,224 Davis; U.S. Pat. No. 4,622,190 Schultz; U.S. Pat. No. 4,726,881 Schultz; U.S. Pat. No. 4,734,236 Davis; U.S. Pat. No. 4,812,188 Hansen; U.S. Pat. No. 4,844,968 Persson; U.S. Pat. No. 4,865,788 Davis; U.S. Pat. No. 4,960,548 Ikeda; U.S. Pat. No. 4,960,553 DeBruine; U.S. Pat. No. 4,969,302 Coggan; U.S. Pat. No. 5,028,374 Imao; U.S. Pat. No. 5,090,173 Coggan; U.S. Pat. No. 5,154,968 DePetris; U.S. Pat. No. 5,443,891 Bach; U.S. Pat. No. 5,851,325 Terada; U.S. Pat. No. 5,887,402 Ruggie;
The cellulosic fibers used to form the loose mat, e.g., a one to two inch, preferably a 1xc2xd or 1xc2xe inch thick layer of cellulosic fibers having a specific gravity of, for example, 0.6, initially may be bone dry after the fibers have been dried and felted, but the cellulosic fibers in such mats absorb moisture from the atmosphere and generally include about 2% to about 10% moisture when molded via hot pressing, depending upon the humidity in the region where such mats are stored and/or manufactured.
The reverse molded panels of the present invention are particularly suitable as wainscot panels. The panels are reverse molded to provide a xe2x80x9cprofile upxe2x80x9d configuration. The reverse molding approach permits mounting the panel directly against a wall versus the prior art method requiring xe2x80x9cshim spacersxe2x80x9d (see FIG. 6A), thereby promoting easy installation while integrating excellent aesthetics of a wainscot panel. Historic treatments of real wood wainscot are well established and very expensive. Beyond the multiple piece millwork of real wood, some gypsum and polymeric materials have been fabricated into wainscot panels, but are marginally commercially acceptable, partly because they do not have the feel or look of natural wood. There are no wood fiber composite reverse molded wainscot systems available that provide the ease of application that is achieved in accordance with the principles of the present invention.
In brief, the present invention is directed to a reverse molded fiberboard panel; a wainscot kit comprising a plurality of differently sized reverse molded panels, and a planar finishing or spacer panel, adapted to completely cover any size wall between a wall base board and a wall chair rail; and a method of reverse molding a loose cellulosic mat, in a single pressing step, to provide one or more relatively high density, raised panels without requiring preliminary pressing, or other pre-shaping step, such as scalping. The reverse-molded panels are molded in a conventional, multi-opening fiberboard press, in a single pressing step process, while achieving excellent transfer of mold detail (embossing fidelity) without visually noticeable fiber fracture. The panels can include a foil, an impregnated paper overlay, or thermoplastic coating materials but do not require an overlay or high resin content coating to achieve excellent embossing fidelity and appearance.
In the preferred embodiment, the loose cellulosic mat that is molded is manufactured by the dry process to provide a smooth, planar back surface surrounding the back surface of the raised, molded panels, rather than a screen back pattern which results from pressed mats made by the wet process. The reverse molded raised panel design provides a raised profile (profile up) that is sharp and crisp with sharp detail in exterior corners that has the appearance and feel of hand crafted natural wood millwork, but actually is a reverse-molded, high density wood composite material that can be adhesively secured to a planar wall, such as gypsum wallboard.
Accordingly, one aspect of the present invention is to provide reverse molded, wood composite articles, and a method of manufacturing the articles, wherein the articles are molded from a loose mat of cellulosic fiber and binder, such that the articles have an upwardly raised panel that simulates natural wood millwork.
Another aspect of the present invention is to provide reverse molded, wood composite articles, and a method of manufacturing the articles, in kit form, such that the articles can be securely adhered to any planar surface, such as a gypsum wallboard, or plaster wall, to fill the entire wall area between a base board and a chair rail, while providing sharp, crisp exterior corners on the reverse molded, raised panel, to simulate natural wood, handcrafted millwork.
Another aspect of the present invention is to provide a wainscot kit comprising a plurality of reverse molded wood composite articles having different widths and a planar panel that can be easily cut to a desired width to fill an entire wall between a base board and a chair rail.
Still another aspect of the present invention is to provide a reverse molded wood composite article that provides exact transferring of mold detail at exterior corners and contours in a single pressing operation without requiring multiple press steps, post mold curing at elevated temperatures, or a foil or a high resin content (5-25%) outer surface portion.
Another aspect of the present invention is to provide reverse molded wood composite articles that can be molded from cellulosic mats that do not require synthetic fibers, scrim surfaces, layering of short and long fibers, resin-impregnated paper overlays, thermoplastic varnishes, or needling (needle punching) to hold the mat together prior to molding.
A further aspect of the present invention is to provide a reverse molded wood composite article that has one or more raised panels including a centrally disposed rectangular panel portion of 5-10 mm in height, surrounded by a raised, molded, contoured millwork design having a plurality of raised, planar steps ascending upwardly and inwardly integral with rounded contours to a rounded top portion that has increased density at a rounded apex, to prevent damage and surface fiber fractures, and has a geometry such that sharp, crisp surface detail is provided, particularly at exterior corners of the millwork geometry, in a single pressing (molding) step, while providing substantially uniform density in all but the rounded apex of the raised, molded rectangular millwork design.
Another aspect of the present invention is to provide a reverse molded wood composite article that can be molded in a strip of multiple parts in a single pressing (molding) operation and can be cut into separate parts after molding and then coated with a water-based and/or solvent-based coating material, e.g., paint or stain.
Still another aspect of the present invention is to provide a wainscot kit that includes a plurality of reverse molded wood composite articles to provide at least two differing raised panel (window) sizes, at least two different composite article widths, wherein a smaller width composite article has a proportionately smaller raised panel width, and a planar spacer panel, so that the combination of composite articles can completely fill a wall between a base board and a chair rail by cutting the planar spacer panel to size at inside wall corners for covering the full wall width up to the chair rail. More particularly, the preferred reverse molded articles in the kit are provided in widths of 12 inches, 16 inches and 48 inches with the 12 inch and 16 inch widths having windows (raised panels) of different sizes; and the 48 inch wide article having three windows of a size to match either the 12 inch wide or 16 inch wide article.
Another aspect of the present invention is to provide a reverse molded wood composite article that has one or more raised panels comprising a central, planar raised portion surrounded by a rectangular raised millwork design, the raised panels being surrounded by planar stiles and rails wherein the raised panels are capable of being separated from the surrounding planar stiles and rails, e.g., via sawing or back sanding, from the surrounding planar base so that the separated panels can be adhered to a household door, cabinet door, shutters, furniture, library or millwork walls, or as a framing material by further removing the central planar raised panel portion.